Heavy duty liquid detergent compositions containing a pair of cellulosic soil suspending agents



United States Patent HEAVY DUTY LIQUID DETERGENT COL [POSI- TIONSCONTAINING A PAIR OF CELLULOSIC SOIL SUSPENDING AGENTS Irving Reich, NewYork, N.Y., and Hans R. Dallenbach,

Coytesville, N.J., assignors to Lever Brothers Company, New York, N.Y.,a corporation of Maine No Drawing. Filed Apr. 15, 1959, Ser. No. 806,429

9 Claims. (Cl. 252-137) The present invention relates to detergentcompositions, and more particularly to concentrated heavy duty liquiddetergent compositions which are uniform stable suspensions showing noseparation into layers at room temperature and which are highlyeffective in preventing soil redeposition when used at washingconcentrations.

Many detergent compositions have heretofore been prepared, but they haveprimarily been in a powdered form and thereby have many disadvantagesenumerated below. Powdered detergent compositions are generally preparedby spray drying or drum drying, which are costly operations. When usedin washing, the powdered detergent compositions must be dissolved toform dilute aqueous washing solutions. This step of dissolving ordispersing the powdered detergent compositions in the wash water is timeconsuming. Frequently, the powdered detergent compositions aredifficultly dispersed, since they may tend to form lumps. Powdereddetergent compositions, moreover, tend to vary greatly in density unlessparticular care is taken in their preparation. Such a variation indensity makes it diflicult to determine the exact amount thereof to beemployed during washing. In addition, powdered deteregnt compositionsmay be difiicult to dispense, since they sometimes clog the orifices ofa dispenser. Also powdered detergent compositions have a tendency tocake at high humidities upon standing in their open containers.Moreover, powdered detergent compositions, being normally sold incardboard containers, are subject to spilling and waste in the event anopen container is accidentally knocked over. Furthermore, theirdustiness may be bothersome, particularly to persons who suffer fromdust allergies.

All of these disadvantages of powdered detergent compositions can beobviated by employing concentrated liquid detergent compositions. Whilelight duty liquid detergent compositions have been prepared heretofore,they have proved to be suitable only for dishwashing and the cleaning offine fabrics. Light duty liquid detergent compositions areunsatisfactory for washing heavily soiled cotton fabrics, since suchcompositions have inadequate soil removal characteristics. Heavy dutyliquid detergent compositions, on the other hand, have excellent soilremoval characteristics and are ideally suited for the washing ofheavily soiled cotton fabrics and other fabrics.

A highly effective heavy duty liquid detergent composition has beenfully described in US. Patent No. 2,859,182 issued November 4, 1958.This homogeneous heavy duty liquid detergent composition consistsessentially of an aqueous solution of a potassium alkylaryl sulfonate,an alkali metal aryl sulfonate, tetrapotassium pyrophosphate orpentapotassium tripolyphosphate, and at least one alkylolamide or anethylene oxide condensation product thereof. The composition may alsohave present therein alkali metal silicates, alkalies, perfumes, dyes,brighteners, and other compatible adjuvants. Complete details concerningthis homogeneous heavy duty liquid detergent composition may readily beobtained by reference to said patent.

This composition could be further improved, if it were possible toincorporate therein soil suspending agents which would prevent orinhibit the redeposition of soil ice upon fabrics Washed repeatedly indiluted wash solutions thereof and thereby avoid greying of the fabrics.Various cellulose derivatives have been used heretofore as soilsuspending agents in powdered detergent compositions. The incorporationof a cellulose derivative into a powdered detergent composition presentsno particular problem, since the detergent composition is in powderedform. The incorporation of cellulosic soil suspending agents in theabove described heavy duty liquid detergent compositions, however, isnot a simple matter.

Thus, when one or a mixture of various cellulose derivatives wereincorporated in the detergent composition, the cellulosic componentseparated out within a few hours and the composition became stratifiedinto two or more layers, one being a clear liquid and the others beingmilky or cloudy. For example, separate samples of the followingrepresentative heavy duty liquid detergent formulation were prepared.

In the above formulation Calcofluor MR and Tinopal RBS are opticalbrighteners which are respectively disodiumN:N'-bis-(2,4-diphenylamino-1:3:5-triazyl [6]) 4:4-diamino stilbene2:2-disulfonate and sodium-2- (stilbyl-4)-(naphtho-l':2':4:5) 1:2:3triazole-2"-sulfonate.

The 0.5% total (except where otherwise indicated) cellulose derivativesin the separate samples was made up as follows: (1) 100% sodiumcarboxymethylcellulose having 0.7 mole of carboxymethyl groups peranhydroglucose unit, (2) 100% low viscosity methylcellulose (25centipoise viscosity in a 2% aqueous dispersion) having 27.5-32%methoxyl groups per cellulose molecule, (3) 100% sodiumcarboxymethylethylcellulose having 0.22 mole of carboxymethyl groups and1.0 mole of ethyl groups per anhydroglucose unit, (4) 100%ethylcellulose having 1.26 moles of ethyl groups per anhydroglucoseunit, (5) 100% sodium carboxymethylmethylcellulose having 0.150.2 moleof carboxymethyl groups per anhydroglucose unit and 14-22% of methoxylgroups per cellulose molecule (0.25% total cellulose derivatives), (6)100% sodium carboxymethylhydroxyethylcellulose having 0.91 mole ofcarboxymethyl groups and 0.50 mole of hydroxyethyl groups peranhydroglucose unit, (7) 57.1% sodium carboxymethylhydroxyethylcellulosehaving 0.91 mole of carboxymethyl groups and 0.50 mole of hydroxyethylgroups per anhydroglucose unit plus 42.9% sodiumcarboxymethylmethylcellulose having 0.l5-0.2 mole of carboxymethylgroups per auhydroglucose unit and 14-22% of methoxyl groups percellulose molecule (0.35% total cellulose derivatives), (8) 40% sodiumcarboxymethylcellulose having 1.94 moles of carboxymethyl groups peranhydroglucose unit plus 60% methylcellulose (25 centipoise viscosity ina 2% aqueous dispersion) having 27.5-32% of methoxyl groups percellulose molecule, (9) sodium carboxymethylhydroxyethylcellulose having0.36 mole of carboxymethyl and 1.07 moles of hydroxyethyl groups peranhydroglucose unit plus 20% methylcellulose (25 centipoise viscosity ina 2% aqueous dispersion) having 27.5-32% of meth- 3 oxyl groups percellulose molecule, (10) 57.1% sodium carboxymethylcellulose having 0.7mole of carboxymethyl groups per anhydroglucose unit plus 42.9% sodium'ca'rboxymethylmethylcellulose having 0.25 mole of carboxymethyl groupsper anhydroglucose unit and 10- 14% of methoxyl groups per cellulosemolecule (0.35% total cellulose derivatives), (11) 60% sodiumcarboxymethylcellulose having 0.7 mole of carboxymethyl groups peranhydroglucose unit plus 40% sodium carboxymethylethylcellulose having0.22 mole of carboxymethyl groups and 1.0 mole of ethyl groups peranhydroglucose unit, (12) 80% sodium carboxymethylcellulose having 0.7mole of carboxymethyl groups per anhydroglucose unit plus 20%ethylcellulose having 1.26 moles of ethyl groups per anhydroglucoseunit, (13) 60% sodium carboxymethylhydroxyethylcellulose having 0.91mole of carboxymethyl groups and 0.50 mole of hydroxyethyl groups peranhydroglucose unit plus 40% of sodium carboxymethylethylcellulosehaving 0.68 mole of carboxymethyl groups and 0.65 mole of ethyl groupsper anhydroglucose unit, (14) 100% methylhydroxypropylcellulose having27-29% methoxyl groups per cellulose molecule and 5.57.5% hydroxypropylgroups per cellulose molecule, (15) 100% methylhydroxypropylcellulosehaving 2830% methoxyl groups per cellulose molecule and 7-12%hydroxypropyl groups per cellulose molecule, and (16) 100%dihydroxypropylcellulose (6100 centipoise viscosity at 25 I C. in a 2%solution in aqueous sodium hydroxide) having 0.3 mole of dihydroxypropylgroups per anhydroglucose unit. In the three instances where the totalcellulose derivatives were lowered below '4 least one alkylolamide or anethylene Oxide condensation product thereof, and a pair of cellulosederivatives as further described below.

The potassium alkylaryl sulfonates have the general formula R,-@SO:K

where R is an alkyl group, which may be saturated or unsaturated andstraight or branched chain, having from 1 to carbon atoms, at least oneR having 8 to 15 carbon atoms, x is a number from 1 to 5, and may be anaverage number. Suitable potassium alkylaryl sulfonates include,

0.5%, the amount of water in the detergent composition was raised acorresponding amount.

' Each of these heavy duty liquid detergent compositions containingeither one or a mixture of cellulose derivatives was allowed to age forone week at room temperature (70-75 F.) Within only one to twenty-fourhours, v

contained cellulose derivatives, they were completely unsuitable becausethey were unstable and separated into layers, thereby presenting anunattractive appearance which would be completely unacceptable to aconsumer, such as a housewife. Containers of the detergent compositionswould have to be shaken prior to use in order to resuspend the separatedcellulosics as best as possible and insure that a dosage poured from thecontainers had the correct amount of cellulosics therein. Moreover, theflecks of cellulosics ultimately combined to form a viscous layer whichwas hard to resuspend even with vigorous shaking.

' It was found quite surprisingly, however, that a concentrated heavyduty liquid detergent composition could be prepared containing cellulosederivatives as soil suspending agents which would be highly efiective inpreventing soil redeposition and greying of fabrics and which would be astable uniform suspension showing no separation into layers at roomtemperature over extended periods, provided the cellulose derivativesoil suspending agents were incorporated in the heavy duty liquiddetergent composition in particular pairs. Accordingly, the heavy dutyliquid detergent compositions of'the invention which are stable uniformsuspensions showing no separation into layers 'at room temperature andwhich are highly eifective in preventing soil redeposition when used atwashing concentrations consist essentially of an aqueous solution offrom about 7% to about 10% of a potassium alkylaryl sulfonate, fromabout 5% to about 8% total of one or more alkali metal aryl sulfonates,

where R and R' taken together with the remainder of the polypropyleneradical form an alkyl group having an i average molecular weightcorresponding to from about 12 to about 15 carbon atoms. The potassiumalkylaryl sulfonate anionic detergent is used in the composition tosupply a portion of the foaming and wetting action necessary in a heavyduty liquid detergent product designed for household use.

The polyphosphate, i.e., tetrapotassium pyrophosphate or pentapotassiumtripolyphosphate, is employed in the composition to supply the heavyduty detergent feature of the liquid, and impart good soil removalproperties thereto. As the amount of polyphosphate is increased, theamount of potassium alkylaryl sulfonate is decreased.

Suitable alkali metal aryl sulfonate or mixtures thereof totaling fromabout 5% to about 8% include the following sodium orv potassium arylsulfonates; toluene sulfonate, tetraliu sulfonate, ethylbenzenesulfonate, isopropylof 15% ortho-xylene sulfonate, 70% meta-xylenesulfonate, and-15% para-xylene sulfonate, a mixture of 47%toluenesulfonate plus 53% of a mixture of 15% ortho-xylene sulfonate,70% meta-xylene sulfonate, and 15% para-xylene.sulfonate, a mixture of22% orthoxylene sulfonate,. 53% meta-xylene sulfonate, 5% parafrom about27% to about 10%, preferably about 20%,

of tetrapotassium pyrophosphate or pentapotassium trixylene sulfonate,18% ethylbenzene sulfonate, and 2% toluene sulfonate, and a mixture offrom about 1% to about 10% toluene sulfonate plus from about 99% toabout of a mixture of 22% ortho-xylene sulfonate, 53% meta-xylenesulfonate, 5% para-xylene sulfonate, 18% ethylbenzene sulfonate, and 2%toluene sulfonate. The alkali metal aryl sulfonate is employed in theheavy duty liquid detergent composition to aid in solubilizing thepotassium. alkylaryl sulfonate in the presence of a considerable amountof the polyphosphate and other inorganic materials. The alkali .metalaryl sulfonate also solubilizes the alkylolamides which are eitherinsoluble in water or incompatible with aqueous solutions ofpolyphosphates. Ihere is no advantage in adding more of the alkali metalaryl sulfonate 'than is necessary for its solubilizing eliect,--sincethis material appears to contribute nothing to the detergent anddishwashing characteristics of the heavy duty liquid detergentcomposition.

The alkylolamide may be either a monoalkylolamide or a dialkylolamide.Typical examples of siutable alkylolamides are lauric isopropanolamide,lauric diethanolamide, coconut monoethanolamide, capric diethanolamide,tallow diethanolamide, and the monoethanolamide of a 1:1 mixture ofcaprylic and capric acids. The alkylolamides act as solubilizers inconjunction with the alkali metal aryl sulfonate to prevent theseparating out from solution of the potassium alkylaryl sulfonate.

Other suitable alkylolamides which may also be employed include ethyleneoxide condensation products thereof, for example, the condensationproduct of one mole of lauric monoethanolamide with one mole of ethyleneoxide and the condensation product of one mole of lauricisopropanolamide with one mole of ethylene oxide. All of the abovealkylolamides may be used either singly or in suitable mixtures.

The heavy duty liquid detergent composition also contains a total offrom about 0.1% to about 3%, and preferably from about 0.25% to about1%, and more preferably from about 0.5% to about 0.7%, of a pair of soilsuspending cellulose derivatives which are simple or mixed lower alkyl,hydroxyalkyl, or carboxyalkyl ethers of cellulose and form a uniformstable suspension in the aqueous solution. These pairs of cellulosicsoil suspending agents include the following: (1) about 9% sodiumcarboxymethylhydroxyethylcellulose having 0.91 mole of carboxymethylgroups and 0.50 mole of hydroxyethyl groups per anhydroglucose unit plusabout 91% sodium carboxymethylmethylcellulose having 0.15-0.2 mole ofcarboxymethyl groups per anhydroglucose unit and 14-22% of methoxylgroups per cellulose molecule, (2) about 8% sodiumcarboxymethylcellulose having 1.94 moles of carboxymethyl groups peranhydroglucose unit plus about 92% methylcellulose (25 centipoiseviscosity in a 2% aqueous dispersion) having 27.532% methoxyl groups percellulose molecule, (3) about 16% sodium carboxymethylcellulose having0.7 mole of carboxymethyl groups per anhydroglucose unit plus about 84%methylcellulose having 3536% methoxyl groups per cellulose molecule, (4)about 20% sodium carboxymethylcellulose having 0.76 mole ofcarboxymethyl groups per anhydroglucose unit plus about 80%methylcellulose (25 centipoise viscosity in a 2% aqueous dispersion)having 27.532% methoxyl groups per cellulose molecule, (5) about 22%sodium carboxymethylcellulose having 0.7 mole of carboxymethyl groupsper anhydroglucose unit plus about 78% methylcellulose (25 centipoiseviscosity in a 2% aqueous dispersion) having 27.5- 32% methoxyl groupsper cellulose molecule, (6) about 44% sodium carboxymethylcellulosehaving 0.7 mole of carboxymethyl groups per anhydroglucose unit plusabout 56% sodium carboxymethylmethylcellulose having 0.25 mole ofcarboxymethyl groups per anhydroglucose unit and -14% methoxyl groupsper cellulose molecule, (7) about 29% sodiumcarboxymethylhydroxyethylcellulose having 0.91 mole of carboxymethylgroups and 0.50 mole of hydroxyethyl groups per anhydroglucose unit plusabout 71% methylcellulose (25 centipoise viscosity in a 2% aqueousdispersion) having 27.532% of methoxyl groups per cellulose molecule,(8) about 44% sodium carboxymethylhydroxyethylcellulose having 0.36 moleof carboxymethyl groups per anhydroglucose unit plus about 56%methylcellulose (25 centipoise Viscosity in a 2% aqueous dispersion)having 27.532% methoxyl groups per cellulose molecule, (9) about 44%sodium carboxymethylhydroxyethylcellulose having 0.73 mole ofcarboxymethyl groups and 0.87 mole of hydroxyethyl groups peranhydroglucose unit plus about 56% methylcellulose (25 centipoiseviscosity in a 2% aqueous dispersion) having 27.532% methoxyl groups percellulose molecule, (10) about 62% methylhydroxypropylcellulose (4000centipoise viscosity in a 2% aqueous dispersion) having 27-29% methoxylgroups per cellulose molecule and 5.5-7.5 hydroxypropyl groups percellulose molecule plus about 38% sodium carboxymethyl cellulose having0.7 mole of carboxymethyl groups per anhydroglucose unit, (11) about 72%methylhydroxypropylcellulose (50 centipoise viscosity in a 2% aqueousdispersion) having 27-29% methoxyl groups per cellu-. lose molecule and5.57.5% hydroxypropyl groups per 'cellulose molecule plus about 28%sodium carboxymethylcellulose having 0.7 mole of carboxymethyl groupsper anhydroglucose unit, (12) about 54% methylhydroxypropylcellulose(4000 centipoise viscosity in a 2% aqueous dispersion) having -2830%methoxyl groups per cellulose molecule and 712% hydroxypropyl groups percellulose molecule plus about 46% sodium carboxymethylcellulose having0.7 mole of carboxymethyl groups per anhydroglucose unit, (13) about 42%methylhydroxypropylcellulose (4000 centipoise viscosity in a 2% aqueousdispersion) having 2729% methoxyl groups per cellulose molecule and5.57.5% hydroxypropyl groups per cellulose molecule plus about 58%dihydroxypropylcellulose having 0.3 mole of dihydroxypropyl groups peranhydroglucose unit, (14) about 64% methylhydroxypropylcellulose (50centipoise viscosity in a 2% aqueous dispersion) having 2729% methoxylgroups per cellulose molecule and 5.57.5% hydroxypropyl groups percellulose molecule plus about 36% dihydroxypropylcellulose having 0.3mole of dihydroxypropyl groups per anhydroglucose unit, and (15) fromabout 70% to about methylcellulose (25 centipoise viscosity in a 2%aqueous dispersion) having 2-7.532% methoxyl groups per cellulosemolecule plus from about 30% to about 10% dihydroxypropylcellulosehaving 0.3 mole of dihydroxypropyl groups per anhydroglucose unit. Itwill be appreciated that the sodium cation on the carboxymethyl group isequivalent to other cations, such as potassium or ammonium or organicamine cations, such as mono-, di-, or vtri-ethanolamine. The substituentcontents given above for the cellulose derivatives are expressed inaverage values.

The remaining component of the heavy duty liquid detergent compositionin water which serves as a solvent for the components thereof.

If desired, the liquid detergent composition may contain minor portionsof an alkali, such as potassium hydroxide, to neutralize any excess acidimpurities present in the components of the composition. In addition,minor portions of compatible perfumes, dyes, optical brighteners, alkalimetal silicates, and other desirable adjuvants may be added to thecomposition. When a water-soluble alkali metal silicate is added to thecomposition, the pH thereof must be adjusted to about 11.4 or above bythe addition of free alkali, such as potassium hydroxide, to keep thesilicate in solution. Typical alkali metal silicates include the sodiumor potassium silicates having the following alkali to silica ratios1:3.92, 1:3.45, 122.4, 1:1.8, 1:25, and 1:20. An amount up to about 6%on a solids basis of the silicate may be employed.

The concentrated heavy duty liquid detergent compo sition of theinvention may be prepared by mixing the components thereof together inthe aqueous medium. Heat may be conveniently utilized during the mixingof the components to increase the rate of dissolution thereof. Apreferred method for the preparation of the stable and uniform heavyduty liquid detergent composition is the addition of the pair ofcellulose derivatives to hot Water followed by cooling to form anaqueous solution thereof and the addition to the cellulose solution ofan aqueous solution of the potassium alkylaryl sulfonate, alkali metalaryl sulfonate, alkylolamide or ethylene oxide condensation productthereof, and any optical brighteners, dyes, alkali, and alkali metalsilicates. The composition is completed by the addition thereto of thetetrapotassium pyrophosphate or pentapotassium tripolyphosphate to givea composition having a pH of about 12. The heavy duty liquid detergentcomposition of the invention will be further illustrated by thefollowing examples.

A representative heavy duty liquid detergent composition was preparedhaving the following formula:

Components Percent by weight Potassium dodecylbenzene sulfonate 1OTetrapotassium pyrophosphate 19.1 Sodium xylene sulfonate (commercial)8. 15 Laurie dief'hannlm'nirio 8 Laurie isoprop 3. 2 Sodium silicate(87%) (N BaQZSlOz of 1:2.5) 7. Calcofluor MR 0. 031 Tinopal RIBS 0. 048Water plus KOH to pH 12.1- 48.171 Total cellulose derivatives 1 0. 50

Total. 100.000

1 Except where otherwise indicated.

Example 1 In this example the 0.5% total cellulosics of therepresentative formula consisted of 8% sodium carboxymethylcellulose (70centipoise viscosity in a 2% aqueous dispersion) having 1.94 moles ofcarboxymethyl groups per anhydroglucose unit plus 92% methylcellulose(25 centipoise viscosity in a 2% aqueous dispersion) having 27.5-32%methoxyl groups per cellulose molecule.

Example 3 In this example the 0.5 total cellulosics of therepresentative formula consisted of 16% sodium carboxymethylcellulose(27 centipoise viscosity in a 2% aqueous dispersion) having 0.7 moles ofcarboxymethyl groups per anhydroglucose unit plus 84% methylcellulosehaving 35-36% methoxyl groups per cellulose molecule.

Example 4 In this example the 0.5 total cellulosics of therepresentative formula consisted of 20% sodium carboxymethylcellulose(3600 centipoise viscosity in a 1% aqueous dispersion) having 0.76 molesof carboxymethyl groups per anhydroglucose unit plus 80% methylcellulose(25 centipoise viscosity in a 2% aqueous dispersion) having 27.532%methoxyl groups per cellulose molecule.

Example 5 In this example the 0.5 total cellulosics of therepresentative formula consisted of 22.6% sodium carboxymethylcellulose(27 centipoise viscosity in a 2% aqueous dispersion) having 0.7 mole ofcarboxymethyl groups 'per anhydroglucose unit plus 77.4% methylcellulose(25 centipoise viscosity in a 2% aqueous dispersion) having 27.5-32%methoxyl groups per cellulose molecule.

Example 6 In this example the total cellulosics of the representativeformula was 0.32% and consisted of 43.7% sodium carboxymethylcellulose(27 centipoise viscosity in a 2% aqueous dispersion) having 0.7 mole ofcarboxymethyl groups per anhydroglucose unit plus 56.3% sodium car-'boxymethylmethylcellulose having 0.25 mole of carboxymethyl groups peranhydroglucose unit and 10-14% methoxyl groups per cellulose molecule.The water in the formula was increased in an amount correspond ing tothe decrease in cellulosic content.

Example 7 In this example the 0.5% total cellulosics consisted of 28.6%sodium carboxymethylhydroxyethylcellulose having 0.91 mole ofcarboxymethyl, groups and 0.50 mole of hydroxyethyl groups peranhydroglucose unit plus 71.4% methylcellulose (25 centipoise viscosityin a 2% aqueous dispersion) having 27.5-32% methoxyl groups percellulose molecule.

Example 8 In this example the 0.5% total cellulosics of therepresentative formula consisted of 44% sodiumcarboxymethylhydroxyethylcellulose having 0.36 mole of carboxymethylgroups and 1.07 moles of hydroxyethyl groups per anhydroglucose unitplus 56% methylcellulose (25 centipoise viscosity in a 2% aqueousdispersion) having 27.5-32% methoxyl groups per cellulose molecule.

Example 9 In this example the 0.5 total cellulosics in therepresentative formula consisted of 44% sodiumcarboxymethylhydroxyethylcellulose having 0.73 mole of carboxymethylgroups and 0.87 mole of hydroxyethyl groups per anhydroglucose unit plus56% methylcellulose (25 centipoise viscosity in a 2% aqueous dispersion)having 27.5- 32% methoxyl groups per cellulose molecule.

Example 10 In this example the total cellulosics in the aboverepresentative heavy duty liquid detergent formulation was increased to0.7% with a decrease of 0.2% in the water content. The 0.7% totalcellulosics consisted of 30% sodium carboxymethylcellulose (27centipoise viscosity in a 2% aqueous dispersion) having 0.7 mole ofcarboxymethyl groups per anhydroglucose unit plus methylcellulose (25centipoise viscosity in a 2% aqueous dispersion) having 27.532% methoxylgroups per cellulose molecule.

Example 11 In this example the 0.5% total cellulosics in the representative formula consisted of 62% methylhydroxypropylcellulose (4000centipoise viscosity in a 2% aqueous dispersion) having 27-29% methoxylgroups per cellulose molecule and 5.5-7.5% hydroxypropyl groups percellulose molecule plus 38% sodium carboxymethylcellulose (27 centipoiseviscosity in a 2% aqueous dispersion) having 0.7 mole of carboxymethylgroups per anhydroglucose unit.

Example 12 In this example the 0.5 total cellulosics in therepresentative formula consisted of 72% methylhydroxypropylcellulose (50centipoise viscosity in a 2% aqueous dispersion) having 27-29% methoxylgroups per cellulose molecule and 5.5-7.5% hydroxypropyl groups percellulose molecule plus 28% sodium carboxymethylcellulose (27 centipoiseviscosity in a 2% aqueous dispersion) having 0.7 mole of carboxymethylgroups per anhydro-' glucose unit.

Example 13 In this example the 0.5 total cellulosics in therepresentative formula consisted of 54% methylhydroxypropylcellulose(4000 centipoise viscosity in a 2% aqueous dis persion) having 2830%methoxyl groups per cellulose molecule and 7-12% hydroxypropyl groupsper cellulose molecule plus 46% sodium carboxymethylcellulose (27centipoise viscosity in a 2% aqueous dispersion) having 07 mole ofcarboxymethyl groups per anhydroglucose unit.

Example 14 In this example the 0.5 total cellulosics in the repre-'Teu-apotassium Pyrophosphate sentative formula consisted of 42%methylhydroxypropylcellulose (4000 centipoise viscosity in a 2% aqueousdispersion) having 27-29% methoxyl groups per cellulose molecule and5.5-7.5 hydroxypropyl groups per cellulose molecule plus 58%dihydroxypropylcellulose (6100 centipoise viscosity at 25 C. in a 2%solution in 5% aqueous sodium hydroxide) having 0.3 mole ofdihydroxypropyl groups per anhydroglucose unit.

Example 15 In this example the 0.5% total cellulosics in therepresentative formula consisted of 64% methylhydroxypropylcellulose (50centipoise viscosity in a 2% aqueous dispersion) having 27-29% methoxylgroups per cellulose molecule and 5.5-7 .5-% hydroxypropyl groups percellulose molecule plus 36% dihydroxypropylcellulose (6100 centipoiseviscosity at 25 C. in a 2% solution in 5% aqueous sodium hydroxide)having 0.3 mole of dihydroxypropyl groups per anhydroglucose unit.

Example 16 In this example the 0.5 total cellulosics in therepresentative formula consisted of 70% methylcellulose (25 centipoiseviscosity in a 2% aqueous dispersion) having 27.532% methoxyl groups percellulose molecule plus 30% dihydroxypropylcellulose 6100 centipoiseviscosity at 25 C. in a 2% solution in 5% aqueous sodium hydroxide)having 0.3 mole of dihydroxypropyl groups per .anhydroglucose unit.

Example 17 In this example the 0.5% total cellulosics in the repre-.sentative formula consisted of 90% methylcellulose (25 centipoiseviscosity in a 2% aqueous dispersion) having 27.532% methoxyl groups percellulose molecule plus dihydroxypropylcellulose (6100 centipoiseviscosity at 25 C. in a 2% solution in 5% aqueous sodium hydroxidehaving 0.3 moles of dihydroxypropyl groups per anhydroglucose unit.

At the end of one weeks storage at room temperature (70-75 F.) all ofthe compositions in Examples 1 through 17 were still uniform stablesuspensions and showed no evidence of separation into layers. Some ofthese compositions were stored for several months at room temperatureand at the end of this period they were still uniform stablesuspensions. Repeat soil redeposition tests showed that all of thesecompositions were highly etfective in preventing soil redeposition andgreying of fabrics. There is reproduced below the data pertaining to ahome laundry repeat washing test utilizing two typical heavy duty liquiddetergent compositions of the invention containing pairs of cellulosederivatives and a composition without the presence of a pair ofcellulose derivatives as a basis of comparison. In this test broadclothwas subjected to a large number of repeat washings in the presence ofnaturally soiled cloth. The reflectance values of the test cloths wereread with a General Electric reflectometer, since this apparatus uses anarrow band of the visible spectrum only and accordingly the presence ofoptical brighteners or fluorescent whitening agents in the testeddetergent formulations does not affect the measured reflectance values.The detergent compositions were as follows:

bat

Potassium Dodeeylbenzene Sulfonate Sodium Xylene Sulfonate (Commercial)Laurie Diethanolamide Laurie Isoptopanolamide" Sodium Silicate. (37%)(NazOZSiOz of 1:2.5)- Calcofluor MR Tlno RBS Water-l-KOH to pH 12.1-.-Total Cellulose Derivatives Reflectance Values Composition 5 Washes 10Washes 20Washes A i 84. 5 80. 3 78. 4 B 84. 2 81. 7 80. 4 O 85. 0 83. 581. 2

The higher reflectance values for the cloth washed 10 or 20 times in thecompositions of the invention (compositions B and C) compared withcomposition A clearly show the compositions of the invention are highlyeffective in preventing soil redeposition and greying of fabrics, sincethey show a significant improvement even at the low levels of total soilavailable from naturally soiled cloth.

The above examples clearly illustrate that the heavy duty liquiddetergent compositions of the invention contain pairs of cellulosederivatives as soil suspending agents, and yet the compositions remainas stable uniform suspensions without separation into layers at the endof one weeks storage at room temperature (7075 F.). Moreover, thecompositions are highly effective in preventing the redeposition of soilfrom soiled fabrics as measured by repeat soil redeposition tests. Itwill be appreciated that in the above examples potassium alkylarylsulfonates, alkali metal aryl sulfonates, polyphosphates, andalkylolamides other than those specifically given in the examples may beused in lieu thereof as specified hereinabove with the same results. Inaddition, the optional optical brighteners, dyes, silicates, andalkalies may be readily omitted from the formulations without destroyingthe essential properties thereof.

It is not clearly understood at this time why individual cellulosederivatives do not form stable suspensions in. the heavy duty liquiddetergent composition nor why certain pairs of cellulose derivatives doform stable suspensions in the heavy duty liquid detergent compositionwhile other pairs of cellulose derivatives are unstable in the heavyduty liquid detergent composition and cause undesirable stratification.It is apparent from photomicrographic studim, however, that the heavyduty liquid detergent compositions of the invention have the cellulosicparticles present therein in a distinctive form. It was observed that inthe cellulose derivative pairs of the invention, the different particlesmerge or react with one another in the aqueous solution to form anetwork or inter-linking aggregation of particles of one cellulosederivative dispersed within the other, thereby forming a combination ofparticles which act as a single entity in producing a stable cellulosicsuspension. This network of particles having one type of particledispersed within the other naturally was absent in the case ofindividual cellulosics and in the case of the cellulosic pairs whichformed unstable suspensions.

This application is a continuation-in-part of our copending applicationSerial No. 619,931, filed November 2, 1956, and now abandoned.

Various modifications and changes may be made in the compositions ofthis invention without departing from the spirit thereof, andaccordingly it will be understood that the invention is to be limitedonly Within the scope of the appended claims.

We claim:

1. A concentrated heavy duty liquid detergent composition which remainsuniform without separation into layers at room temeprature and which ishighly effective 1 1 in preventing soil redeposition when used atwashing concentrations consisting essentially of an aqueous solution of(1) from about 7% to about 10% of a potassium alkylaryl sulfonate havingthe general formula Rr-GSOSK where R is an alkyl group containing from 1to 15 carbon atoms, at least one R having 8 to 15 carbon atoms, and x isa number from 1 to (2) from about 5% to about 8% total of alkali metalaryl sulfonate selected from the group consisting of toluene sulfonate,tetralin sulfonate, ethylbenzene sulfonate, isopropylbenzene sulfonate,ortho-xylene sulfonate, meta-xylene sulfonate, a mixture of 80% toluenesulfonate and 20% ethylbenzene sulfonate, a mixture of 61% ortho-xylenesulfonate and 39% isopropylbenzene sulfonate, a mixture of 15%orthoxylene sulfonate, 70% meta-xylene sulfonate, and 15% para-xylenesulfonate, a mixture of 47% toluene sulfonate plus 53% of a mixture of15 ortho-xylene sulfonate, 70% meta-xylene sulfonate, and 15%para-xylene sulfonate, a mixture of 22% ortho-xylene sulfonate, 53%meta-xylene sulfonate, 5% para-xylene sulfonate, 18% ethylbenzenesulfonate, and 2% toluene sulfonate, and a mixture of from about 1% toabout toluene sulfonate plus from about 99% to about 90% of a mixture of22% ortho-xylene sulfonate, 53% meta-xylene sulfonate, 5% para-xylenesulfonate, 18% ethylbenzene sulfonate, and 2% toluene sulfonate; (3)from about 27% to about 10% of a potassium polyphosphate selected fromthe group consisting of tetrapo-tassium pyrophosphate and pentapotassiumtripolyphosphate; (4) from about 4% to about 7% total of at least onecompound selected from the group consisting of lauric isopropanolamide,lauric diethanolamide, coconut monoethanolamide, capric diethanolarnide,tallow diethanolamide, the monoethanolamide of a 1:1 mixture of caprylicand capric acids, the condensation product of one mole of lauricmonoethanolamide with one mole of ethylene oxide, and the condensationproduct of one mole of lauric isopropanolamide with one mole of ethyleneoxide; and (5 and 6) from about 0.1% to about 3% total of a pair of soilsuspending cellulose ethers selected from the group consisting of simpleand mixed lower alkyl, hydroxyalkyl, and carboxyalkyl ethers ofcellulose, which ethers form with One another in the aqueous solution anetwork of particles of one cellulose ether dispersed within the other.

2. A concentrated heavy duty liquid detergent composition which remainsuniform without separation into layers at room temperature and which ishighly efiective in preventing soil redeposition when used at washingconcentrations consisting essentially of an aqueous solution of (1) fromabout 7% to about 10% of a potassium alkylaryl sulfonate having thegeneral formula where R is an alkyl group containing from 1 to carbonatoms, at least one R having 8 to 15 carbon atoms, and x is a numberfrom 1 to 5; (2) from about 5% to about 8% total'of alkali metal arylsulfonate selected from the group consisting of toluene sulfonate,tetralin sulfonate, ethylbenzene sulfonate, isopropylbenzene sulfonate,orthoxylene sulfonate, meta-xylene sulfonate, a mixture of 80% toluenesulfonate and ethylbenzene sulfonate, a mixture of 61% ortho-xylenesulfonate and 39% isopropylbenzene sulfonate, a mixture of 15%ortho-xylene sulfonate, 70% meta-xylene sulfonate, and 15% paraxylenesulfonate, a mixture of 47% toluene sulfonate plus 53% of a mixture of15% ortho-xylene sulfonate, 70% meta-xylene sulfonate, and 15%paraxylene sulfonate, a mixture of 22% ortho-xylene sulfonate, 53%meta-xylene sulfonate, 5% para-xylene sulfonate, 18% ethylbenzenesulfonate, and 2% toluene sulfonate, and a mixture of -f rom about 1% toabout 10% toluene su]fo (5 12 nate plus from about 99% to about 90% of amixture of 22% ortho-xylene sulfonate, 53% meta-xylene sulfonate, 5%para-xylene sulfonate, 18% ethylbenzene sulfonate, and 2% toluenesulfonate; (3) from about 27% to about 10% of a potassium polyphosphateselected from the group consisting of tetrapotassium pyrophosphate andpentapotassium tripolyphosphate; (4) from about 4% to about 7% total ofat least one compound selected from the group consisting of lauricisopropanolamide, lauric diethanolamide, coconut monoethanolamide,capric diethanolarnide, tallow diethanolamide, the monoethanolamide of a1:1 mixture of caprylic and capric acids, the condensation product ofone mole of lauric monoethanolamide with one mole of ethylene oxide, andthe condensation product of one mole of lauric isopropanolamide with onemole of ethylene oxide; and (5 and 6) from about 0.1% to about 3% totalof a pair of cellulose derivatives selected from the group consisting ofabout 9% sodium carboxymethylhydroxyethylcellulose having 0.91 mole ofcarboxymethyl groups and 0.50 mole of hydroxyethyl groups peranhydroglucose unit plus about 91% sodium carboxymethylmethylcellulosehaving 0.l5-0.2 mole of carboxymethyl groups per anhydroglucose unit and14- 22% of methoxyl groups per cellulose molecule, about 8% sodiumcarboxymethylcellulose having 1.94 moles of carboxymethyl groups peranhydroglucose unit plus about 92% methylcellulose of 25 centipoiseviscosity in a 2% aqueous dispersion having 27.5-32% methoxyl groups percellulose molecule, about 16% sodium carboxymethylcellulose hazving 0.7mole of carboxymethyl groups per anhydroglucose unit plus about 84%methylcellulose having 3536% methoxyl groups per cellulose molecule,about 20% sodium carboxymethylcellulose having 0.76 mole ofcarboxylmethyl groups per anhydroglucose unit plus about methylcelluloseof 25 centipoise viscosity in a 2% aqueous dispersion having 27.532%methoxyl groups per cellulose molecule, about 22% sodiumcarboxymethylcellulose having 0.7 mole of carboxymethyl groups peranhydroglucose unit plus about 78% methylcellulose of 25 centipoiseviscosity in a 2% aqueous dispersion having 27.5-32% methoxyl groups percellulose molecule, about 44% sodium carboxymethylcellulose having 0.7mole of carboxymethyl groups per anhydroglucose unit plus about 56%sodium carboxymethylmethylcellulose having 0.25 mole of carboxymethylgroups per anhydroglucose unit and 1014% methoxyl groups per cellulosemolecule, about 29% sodium' carboxymethylhydroxyethylcellulose having0.91 mole of carboxymethyl groups and 0.50 mole hydroxyethyl groups peranhydroglucose unit plus about 71% methylcellulose of 25 centipoiseviscosity in a 2% aqueous dispersion having 27.5- 32% methoxyl groupsper cellulose molecule, about 44%sodiumcarboxymethylhydroxyethylcellulose having 0.36 mole ofcarboxymethyl groups and 1.07 moles of hydroxyethyl groups peranhydroglucose unit plus about 56% methylcellulose of 25 centipoiseviscosity in a 2% aqueous dispersion having 27.532% methoxyl groups percellulose molecule, about 44% sodium carboxymethylhydroxyethyleellulosehaving 0.73 mole of carboxymethyl groups and 0.87 mole of hydroxyethylgroups per anhydroglucose unit plus about 56% methylcellulose of 25centipoise viscosity in a 2% aqueous dispersion having 27.5-32% methoxylgroups per cellulose molecule, about 62% methylhydroxypropylcellulose of4000 centipoise viscosity in a 2% aqueous dispersion having 27-29%methoxyl groups per cellulose molecule and 5.5-7.5 hydroxypropyl groupsper cellulose molecule plus about 38% sodium carboxymethylcellulosehaving 0.7 mole of carboxymethyl groups per anhydroglucose unit, about72% methylhydroxypropylcellulose of 50 centipoise viscosity in a 2%aqueous dispersion having 27-29% methoxyll groups per celluose moleculeand 5.57.5% hydroxypropyl groups per cellulose molecule plus about 28%sodium carboxymethylcellulose having 07 mole of carboxymethyl groups peranhydroglucose unit, about 54% methylhydroxypropylcellulose of 4000centipoise viscosity in a 2% aqueous dispersion having 28-30% methoxylgroups per cellulose molecule and 7-12% hydroxypropyl groups percellulose molecule plus about 46% sodium carboxylmethylcellulose having0.7 mole of carboxymethyl groups per anhydroglucose unit, about 42%methylhydroxypropylcelluose of 4000 centipoise viscosity in a 2% aqueousdispersion having 27-29% methoxyl groups per cellulose molecule and5.5-7.5% hydroxypropyl groups per cellulose molecule plus about 58%dihydroxypropylcellulose having 0.3 mole of dihydroxypropyl groups peranhydroglucose unit, about 64% methylhydroxypropylcellulose of 50centipoise viscosity in a 2% aqueous dispersion having 27-29% methoxylgroups per cellulose molecule and 5.5-7.5% hydroxypropyl groups percellulose molecule plus about 36% dihydroxypropylcellulose having 0.3mole of dihydroxypropyl groups per anhydroglucose unit and from about70% to about 90% methylcellulose of 25 centipoise viscosity in a 2%aqueous dispersion having 27.532% methoxyl groups per cellulose moleculeplus from about 30% to about 10% dihydroxypropylcellulose having 0.3mole of dihydroxypropyl groups per anhydroglucose unit.

3. A concentrated heavy duty liquid detergent composition as set forthin claim 2 wherein the pair of cellulose derivatives totals about 0.5%.

4. A concentrated heavy duty liquid detergent composition as set forthin claim 2 wherein the pair of cellulose derivatives totals about 0.7%and consists of about 30% sodium carboxymethylcellulose having 0.7 moleof carboxymethyl groups per anhydroglucose unit plus about 70%methylcellulose having a viscosity of 25 centipoises in a 2% aqueousdispersion and having 27.532% methoxyl groups per cellulose molecule.

5. A concentrated heavy duty liquid detergent composition as set forthin claim 3 wherein the pair of cellulose derivatives is about 22% sodiumcarboxymethylcellulose having 0.7 mole of carboxymethyl groups peranhydroglucose unit plus about 78% methylcellulose of 25 centipoiseviscosity in a 2% aqueous dispersion having 27.5- 32% methoxyl groupsper cellulose molecule.

6. A concentrated heavy duty liquid detergent composition as set forthin claim 3 wherein the pair of cellulose '14 derivatives is about 8%sodium carboxymethylcellulos having 1.94 moles of carboxymethyl groupsper anhydroglucose unit plus about 92% methylcellulose of 25 centipoiseviscosity in a 2% aqueous dispersion having 27.5- 32% methoxyl groupsper cellulose molecule.

7. A concentrated heavy duty liquid detergent composition as set forthin claim 3 wherein the pair of cellulose derivatives is about 29% sodiumcarboxymethylhydroxyethylcellulose having 0.91 mole of carboxy-methylgroups and 0.50 mole of hydroxyethyl groups per anhydroglucose unit plusabout 71% methylcellulose of 25 centipoise viscosity in a 2% aqueousdispersion having 27.5- 32% methoxyl groups per cellulose molecule.

8. A concentrated heavy duty liquid detergent compo sition as set forthin claim 3 wherein the pair of cellulose derivatives is about 9% sodiumcarboxymethylhydroxyethylcellulose having 0.91 mole of carboxymethylgroups and 0.50 mole of hydroxyet-hyl groups per anhydroglucose unitplus about 91% sodium carboxymethylmethylcellulose having 0.150.2 moleof carboxymethyl groups per anhydroglucose unit and 14-22% methoxylgroups per cellulose molecule.

9. A concentrated heavy duty liquid detergent composition as set forthin claim 3 wherein the pair of cellulose derivatives is from about toabout methylcellulose of 25 centipoise viscosity in a 2% aqueousdispersion having 27.5-32% methoxyl groups per cellulose molecule plusfrom about 30% to about 10% dihydroxypropylcellulose having a viscosityof 6100 centipoises at 25 C. in a 2% solution in 5% aqueous sodiumhydroxide and having 0.3 mole of dihydroxypropyl groups peranhydroglucose unit.

References Cited in the file of this patent UNITED STATES PATENTS Re.23,840 Vitale et a1. June 15, 1954 2,581,677 Machlis et a1 Jan. 8, 19522,618,632 Klug Nov. 18, 1952 2,733,214 Vitale et a1. Jan. 31, 19562,860,107 Lamberti et a1 Nov. 11, 1958 FOREIGN PATENTS 678,445 GreatBritain Sept. 3, 1952

1. A CONCENTRATED HEATY DUTY LIQUID DETERGENT COMPOSITION WHICH REMAINSUNIFORM WITHOUT SEPARATION INTO LAYERS AT ROOM TEMPERATURE AND WHICH ISHIGHLY EFFECTIVE IN PREVENTING SOIL REDEPOSITION WHEN USED AT WASHINGCONCENTRATIONS CONSISTING ESSENTIALLY OF AN AQUEOUS SOLUTION OF (1) FROMABOUT 7% TO ABOUT 10% OF A POTASSIUM ALKYLARYL SULFONATE HAVING THEGENERAL FORMULA